Energy harvesting devices generate electrical power from energy sources that are often overlooked and untapped. Examples of energy sources and methods to convert electricity include photovoltaic devices which convert light energy into electricity, cantilevered piezoelectric beams which convert vibrational energy into electricity and thermoelectric devices which convert heat flow into electricity. These energy harvesting devices and methods are amenable to a variety of applications.
As low power electronics become increasingly prevalent, energy harvesting devices and methods provide a useful way to power electronic devices without the need for batteries or electrical wiring. Electrical wiring is undesirable in many applications due to its cost to design and install, as well as its weight and difficulty to retrofit. Batteries are undesirable on airplanes due to the difficulty of replacement and because some batteries pose environmental or safety hazards. Additionally, batteries typically function poorly in low temperatures. In some cases, electronic devices that occasionally require medium quantities of electrical power may be powered using low-power energy harvesting devices. In these cases, electrical energy generated by energy harvesting devices is stored in a capacitor or rechargeable battery.